Dual TBridge Percussion

Contents

Concept

The TBridge circuit was used in some famous analog drumcomputers. It is possible to create different drumsounds like bassdrums, toms, claves and more. The circuit was developed during the Homemade summercamp 2014 in Fou de Fougerette by Uwe Schueler, Tamara Wilhelm and Oliver Jaeggi.

On the board are 2 TBridge sounds circuits that can be played separately.

Parts

IC TL082P op-amp (or similar)

resistors

R1 100k RESISTOR

R2 100k RESISTOR

R3 100k RESISTOR

R4 10 RESISTOR

R5 1.9M RESISTOR

R6 3.8M RESISTOR

R7 100k RESISTOR

R8 100k RESISTOR

R9 100k RESISTOR

R10 10 RESISTOR

R11 1.9M RESISTOR

R12 3.8M RESISTOR

R13 100k RESISTOR

R14 100k RESISTOR

R15 1k RESISTOR

P1, 2 1k. POTENTIOMETER for frequency of the percussion sound

capacitors

C1 100n NONPOL (C1B for wider cap)

C2 100n NONPOL (C2B for wider cap)

C3 100n NONPOL (C3B for wider cap)

C4 100n NONPOL (C4B for wider cap)

C5 10n NONPOL

C6 10n NONPOL

C7 4.7u POL

C8 4.7u POL

C9 47u POL

2* switches (on-off-on) select the decay ranges

5* jack connectors (2 * trigger in / 2 * boom out / mix out)

Schematics

A Dual OpAmp is used for 2 TBridge Oscillators. The Potentiometer controlls the frequency of the oscillator. The decayswitch selects different decay times of the sound (this also affects the frequency).

Board

Built Devices

Dual TBridge Percussion device with piezo triggerpad to play the sounds by hand. The sounds can also be triggered by an external trigger signal. The piezo trigger pads have also trigger outputs to play external gear.